Data is often distributed to scale the storage capacity or processing capacity of systems that provide access to the data. For example, database tables or other data objects can be divided into partitions in order to leverage the capacity of different hosts, such as different servers or other computing devices, to separately provide access to individual partitions. Distributed storage can also provide the opportunity to change the configuration or partitioning of data, such as by increasing, decreasing, or otherwise changing the location of data by migrating items of data from one location to another. Migrating items, however, can impede the performance of distributed systems by blocking or delaying access to partitions of data that are migrated. Techniques that can provide migration techniques that minimize or eliminate the impact upon the ability of users to access data are, therefore, highly desirable.
While embodiments are described herein by way of example for several embodiments and illustrative drawings, those skilled in the art will recognize that the embodiments are not limited to the embodiments or drawings described. It should be understood, that the drawings and detailed description thereto are not intended to limit embodiments to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope as defined by the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include”, “including”, and “includes” mean including, but not limited to.